Four wild fish advocacy groups plan to sue over an unused weir at the Lower Elwha Klallam tribe’s hatchery on the Elwha River, saying that its lack threatens wild fish and violates the Endangered Species Act.

The weir was designed to separate wild salmon species from those raised in the hatchery.

“That weir was an integral part of their plan. If they can’t use it, their plan can no longer function as designed,” said Kurt Beardslee, executive director of the Wild Fish Conservancy based in Duvall.

The conservancy, along with The Conservation Angler, the Federation of Fly Fishers Steelhead Committee and the Wild Steelhead Coalition sent letters to the tribe and five federal agencies Thursday.

They said that they plan to file a suit in federal court in 60 days if the agencies and the tribe do not fix operations at the hatchery.

Letters were sent to the tribe and to the federal National Oceanic and Atmospheric Administration National Marine Fisheries Service, the National Park Service and the U.S. Fish and Wildlife Service, as well as to the Department of the Interior and the U.S. Department of Commerce, the latter two having oversight over other named agencies.

Steve Suagee, general counsel for the Lower Elwha Klallam tribe, had not seen the letter until called for comment by the Peninsula Daily News on Friday and said he could not comment without looking into the allegations.

Hatchery personnel and the government agencies could not be reached for comment Friday.

The weir was part of the $16.5 million hatchery operation built to boost Elwha River fish runs as part of the $325 million river restoration project begun in 2011.

It included the largest dam removal project in U.S. history. The dams, built to generate electrical power, had blocked salmon migration for a century because they were constructed without fish ladders.

The dams cut legendary salmon runs, said to have been in the hundreds of thousands, to fewer than 3,000.

The oldest of the two dams, the Elwha Dam, was demolished by March 2012 and the once-210-foot-tall Glines Canyon Dam farther upstream, which was built in 1927, is down to 35 feet and is expected to be completely taken down later this year.

The groups say the weir was removed because it was not working properly.

Without the weir in place, the survival of wild chinook salmon, steelhead and bull trout is threatened, the group said.

The Elwha River chinook are part of the Puget Sound stock, which is listed as threatened under the federal Endangered Species Act, according to the Olympic National Park.

In 2007, Puget Sound steelhead was listed as threatened under the Endangered Species Act and the river’s bull trout population also is considered threatened under the act, the park says on its website, www.nps.gov/.

Without the weir’s separation, the groups allege, wild fish are threatened by hatchery fish who compete for food and spawning space, and who mate with wild fish.

That introduces “maladaptive genes” to the wild steelhead and chinook salmon, the conservationists say.

In April, a panel of federal appellate judges rejected the group’s request for an injunction to stop planting of hatchery-bred fish in the Elwha River.

The group also settled a suit with the state Department of Fish and Wildlife that stopped the planting of the Chambers Creeks species of steelhead in several rivers that drain into Puget Sound, including the Dungeness.

In the wake of that suit, some 900,000 Chambers Creek steelhead were removed from Puget Sound hatcheries and planted in Sprague Lake west of Spokane.

Earlier this month, the same conservation groups filed a letter of intent to sue against the United States Fish and Wildlife Service, the United States Bureau of Reclamation, and the Bonneville Power Administration, claiming their operation of the Leavenworth National Fish Hatchery violated the Endangered Species Act.